A display device is a device for displaying characters, numbers, symbols, pictures or images formed by at least two selected from a group comprising characters, numbers, symbols and pictures. The display device can be a flat surface display device, a curved-surface display device, a 3D display device, a near eye display device, or an enhanced reality (AR)/virtual reality (VR) display device, etc.
With the development of display devices, more and more sophisticated demands are brought out by people with the on-the-spot effect of display and the immersion of viewers. In order to improve the on-the-spot effect of display and the immersion of the viewer, one of the key technologies is to effectively control light propagation within the display device. For example, with respect to a display device for 3D display, the display device has a fixed left-eye field-of-view central area and right-eye field-of-view central area, wherein the left-eye field-of-view central area and a non left-eye field-of-view central area together form a light exiting surface of the whole display device, and the right-eye field-of-view central area and a non right-eye field-of-view central area also together form a light exiting surface of the whole display device. When a viewer is in a viewing area in front of the display device and is viewing an image displayed by the display device, a left-eye sight of the viewer concentrates on the left-eye field-of-view central area, and a right-eye sight of the viewer concentrates on the right-eye field-of-view central area. By controlling light propagation within the display device, the image viewed by the viewer seem to be projected on a virtual screen in front of or behind the display device, and the viewer is enabled to see the image displayed by the whole display device, thus realizing virtual display of the display device, which makes the display device to have a good on-the-spot effect and can improve the immersion of the viewer.
At present, microprisms or microlenses are usually provided in the display device to control light propagation within the display device. That is, the existing display device usually uses structures designed on the basis of geometrical optics principles to realize control to light propagation within the display device. However, with the development of 3D display devices, structures designed on the basis of geometrical optics principles can no longer meet the requirements on the control to light propagation within the display device, so the on-the-spot effect of the display device and the immersion of the viewers get worse, and bad viewing experience is brought to the viewers.